Temperature-alarm



(No Model.)

L. ZAGELMEYER.

TEMPERATURE ALARM No. 451,548. Patented May 5,- 1891.

[/1/1 M1/ or" wfwssw L 0m Z a/yeim/e yer UNITED STATES PATENT ()rmcn.

LOUIS ZAGELMEYER, OF VEST BAY CITY, MICHIGAN.

TEMPERATURE-ALARM.

Application filed December 8, 1890. Serial No. 373,922. (No model.)

To all whom it may concern:

Be it known that I, LOUIS ZAGELMEYER, a citizen of the United States, residing at Vest Bay City, in the county of Bay and State of Michigan, have invented certain new and useful Improvements in Temperature-Alarms, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to new and useful improvements in a combined electric temperature-alarm and thermometer; and the invention consists in the peculiar construction, arrangement, and operation of the thermostatic device and in its peculiar combination with an electric alarm, whereby extreme temperatures close the electric circuit and sound the alarm, while at the same time the device forms a thermometer adapted as well for indicating the temperature in degrees of heat as for indicating maximum and minimum temperatures, all as more fully hereinafter described, and specifically set forth in the claims.

In the drawings, Figure 1 is a perspective View of my device. Fig. 2 is a vertical central section thereof. Fig. 3 is a similar view showing the device slightly modified.

A is a base-plate, preferably of wood or other insulating material.

B is a standard secured in the base.

G is the spiral coil consisting of a compound metal strip composed of two or more different metals having unequal expansion.

1) is an arm integrally formed or secured to the lower end of the spiral coil, the upper end of the spiral coil being secured to or fastened adjustably to the upper end of the standard.

E and E are a pair of index-hands sleeved upon the foot of the standard and electrically insulated therefrom by a block of insulating material F, which is also adapted to hold the index-hands E E in any adjusted position by frictional engagement therewith.

G is a thermometric scale secured to the base A.

II is an electric alarm.

I is a suitable battery, and K is the electric circuit of the battery, and K K is the electric circuit in which the battery and alarm are placed, one part of the battery being electrically connected in any suitable manner to the index-hands E E, while the other pole is electrically connected to the spiral coil 0.

The ind ex-hands E E are adapted to be circularly adjusted around the foot of the stand ard, and for the purpose of my invention 1 make the degrees of frictional resistance which they oppose with their being moved adjustable by any suitable means-as, for instance, shown in Fig. 2, wherein L is a tubular sleeve upon the standard B, and M a S016\ nut engaging with the threaded upper end of the standard, whereby by means of the nut and interposed sleeve L the insulating-block F, made of rubber or other compressible or insulatin g material, may be compressed more or less, clamping the index-hands E E slightly or firmly, for the purpose hereinafter described; butitmay be accomplished as shown in Fig. 3, in which the compressible insulating-block F can be more or less compressed by a nut M on the screw-threaded portion of the lower end of the standard.

For a further object of my invention I make the spiral coil 0 rotatorily adjustable upon the standard 13 in any suitable manner, such as shown in Figs. 2 or 3. In the former drawing the upper end of the coil 0 is secured to the sleeve L, and the sleeve has on its upper end a knob N, whereby the sleeve L and coil 0 may be rotatorily adjusted upon the standard.

In Fig. 3 the upper end of the coil 0 is secured to a collar 0. It is detachably secured upon the upper standard by a set-screw P. I preferably also provide a switch Q in the electric circuit, whereby the alarm may be connected or disconnected, the switch Q in the drawings being shown connected at its fast end through a metallic connection with a washer R on top of the insulating-block F, while the movable end of the switch is adapted to form a make-and-break connection with the metallic contact which forms one pole of the battery, the other pole of the battery being in any suitable manner electrically connected with the index-fingers E E, such as by means of the metallic strip T, extending underneath the near ends of the index-fingers.

The free end of the arm D is suitably constructed to form a metallic contact with at the upper end of the standard.

either of the hands E E, the latter of which to this end are provided with suitable contact-pieces U U.

Suitable ears or lugs V are preferably attached to the base to secure the device readily with the sills of a room, the parts being constructed and arranged substantially as shown and described. They are intended to operate as follows: The fluctuation of heat causes the armD of the spiral coil to move in the arc of a circle, and provided the spiral coil is made sufliciently long and composed of metals having a large degree of difference in their coeflicient of expansion very small fluctuations in the temperature will produce a very perceptible movement in the arm D, as the other end of the spiral coil is held fast This movement of the arm D will close the electric circuit and ring an alarm whenever it comes in contact with either one of the contacts U and U on the index-hands E E. If the scale G is properly devised to express the movement of the arm D in degrees of temperature, it will be seen that it it is desired to ring an alarm when the temperature in the room becomes too high or too low the indexhands E E have merely to be set to correspond to the desired maximum and minimum temperatures, when the alarm will be rung when either extreme of temperature takes place, any accidental displacement of the index-handsEE being prevented by clamping them fast in the manner before described; but if it is desired to indicate maximum and minimum temperatures the frictional resistance of the arms E E is reduced to a mini mum, so that the arm D may be able to carry them to the most extreme point.

If it is desired to ascertain the temperature of the room at any time, one of the indexhands E E is carefully moved toward the arm D until contact is made therewith or either alarm sounded, when the exact temperature may be read off from the scale. In this manner the coil 0 may be adjusted to give correct reading by comparing it with an ordinary thermometer, the indications of which are known to be correct. Thus if a true thermometer indicates a temperature of in the room, the arm D should be in exact contact with either one of the index-hands E orE' upon moving such index-hand to 70 on the scale. If this is not the case, the coil 0 must be adjusted, and to this end the provision for the rotarily adjusting the coil has been provided. This adjustment is also useful for adapting the instrument to indicate higher or lower ranges of temperatures, as it will be seen that by placing two or more scales upon the base the scope of the instrument may be greatly extended, and thus the usefulness of the device for different purposes may be greatly enlarged, it being well known that this class of thermometers is best adapted for indicating between varying extended limits of temperatures.

I am aware that the expansion and contraction of metals have been used heretofore to indicate the degree of temperature; but on account of the small coefficient of expansion and contraction of metals very delicate multiplying devices had to be employed to express the variations of temperature in suitably large divisions on the scale, and on this account thermometers were either very elaborate or very expensive.

In my construction the use of the spirallycoiled compound metal strip gives direct measurable results, which are still further multiplied without any loss of accuracy by the employment of the index-hands.

My device is not only very sensitive under rapid fluctuations of temperature, but the ease of adjustment to give correct indications makes it superior to the ordinary thermometers. It will be also seen that by providing the device with an electric switch the annoyance of night-alarms may be avoided. At the same time the device forms a convenient electrical call-bell.

\Vhat I claim as my invention is- 1. In a thermometric electrical instrument, the combination, with the base, of a thermostatic coil loosely sleeved upon a standard and having one end secured thereto, a radial arm formed on the other end of said coil, two index-hands frictionally secured on a pivot in the axis of the coil, and a thermometric scale for adjusting the index-hands and the arm of the coil, substantially as described.

2. In a thermometric electrical instrument, the combination, with the base, of a thermostatic spiral coil loosely sleeved upon the standard and having one end adj ustably secured thereto, a radial arm formed on the other end of said coil, two index-hands frictionally secured on a pivot in the axis of the coil and extending radially beyond the arm of the coil on opposite sides thereof, respectively, means for increasing or diminishing the frictional engagement of the index-hands on their pivot, and an electric alarm in normally-open circuit with said index-hands and with the coil, substantially as described.

3. In a thermometric electrical instrument, the combination of the base, the thermostatic spiral coil rotarily adj ustably mounted upon a standard on the base and having its upper end secured thereto and its lower end provided with a radial arm, two index-hands pivotally mounted on the foot of the standard and projecting beyond the arm of the coil on opposite sides thereof, respectively, the metallic contacts formed on the arm of the coil and on the index-hands, and the electric alarm having one pole of its circuit electrically connected to the contacts on the index-hands and the other to the contact of the arm on the coil, substantially as described.

4;. In a thermometric electrical instrument, the combination of the base, the standard secured thereto, the thermostatic spiral coil having its upper end secured to a sleeve or collar adjustably secured upon said standard and having its lower end provided with a radial arm, an electric alarm having one pole of its circuit electrically connected to said arm, the index-hands extending from the standard, means adapted to form a frictional resistance to hold the index-hands in their adjusted positions, the scale for the indexhands, and the metallic contacts 011 such inl 

